1. Field of the Invention
The present invention relates to a control system for providing interactive information services, such as video, audio, library, interactive games, and the like. Particular video applications include "movie on demand", on-line data retrieval, and shop at home. The information services in accordance with the invention all require the use of an interactive connection between a services provider or another user and the customer's set top terminal over a network. More particularly, the invention relates to a control system for establishing an information session connection between the customer's set top terminal and the service provider or other user over a network and then managing the bi-directional network communications necessary to provide the interactive information services to the customer.
2. Description of the Prior Art
Recent advances in digital signal processing techniques and, in particular, advancements in digital compression techniques, have led to a plethora of proposals for providing new digital services to the customer's home via existing telephone and coaxial cable lines. For example, it has been proposed to provide hundreds of CATV channels to customers by compressing digital video, transmitting the compressed digital video over conventional coaxial CATV cables, and then decompressing the video at the customer's set top terminal. Another proposed application of this technology is a "movie on demand" video system in which a customer communicates directly with a video service provider via the telephone lines to request a particular video program from a video library and the requested video program is routed to the caller's home via the telephone lines or via the coaxial CATV cables for immediate viewing.
For example, an interactive television system of this type has been described by Pocock et al. in U.S. Pat. No. 5,014,125 which employs a two-way telephone connection to send command signals from a viewer to a central controller for selecting various video programs and for sending the audio portion of such video programs from a central location to the viewer. Once the connection is established, a transmission path connecting the viewer to the central location is identified and its ID is sent from the viewer's set top terminal to the central controller. This transmission path is then used to control the transmission of the video programming to the viewer's terminal, where the programming is stored and retransmitted to the viewer's television. Once the transmission of the video program has started, address and command data may be sent from the video service provider to the viewer's set top terminal in the vertical blanking interval of the video frames. Unfortunately, however, the system described by Pocock et al. requires the use of the telephone lines to transmit commands from the set top terminal to the central controller and thus requires use of the telephone standards and protocols under control of the telephone companies for the transmission of the commands. Moreover, the Pocock et al. system is interactive only in the sense that the viewer may request a particular video program. The viewer may not interact with the video program during transmission using commands such as Play, Pause, Fast Forward, and the like as when the program is locally controlled via the viewer's video cassette recorder (VCR).
In U.S. Pat. No. 5,235,619 to Beyers, II et al., assigned to the same assignee as the present application, an RF return method is described in which data is transmitted over a plurality of selectable data channels having carrier frequencies which are located within a television bandwidth channel reserved for upstream transmission from a CATV subscriber to a headend control location. As described therein, the upstream transmit levels are automatically set on a periodic basis and transmit times are selected in which at least one time is random. These return path channels are used for video conferencing, power meter reading, alarm services, subscriber polling and voting, collecting subscriber viewing statistics, home shopping, and impulse pay-per-view services. However, to date, such RF return paths have been used for billing data and the like which are sent on a periodic basis and have not been adapted to provide a completely interactive information session connection between a CATV subscriber and the information provider (or another CATV subscriber) whereby commands and data flow back and forth in real-time.
Many believe that a truly interactive system in which a customer can selectively access a large audio, video or data library and control the presentation of the selected information on a real-time basis, as when the video program is played back using the viewer's VCR, or in which one customer may interact with another customer, as in the case of interactive video games, long distance learning, and the like, will revolutionize the way people acquire information and receive entertainment. Unfortunately, prior to the present invention, a communication system and protocol have not been established which will permit the implementation of a "movie on demand" system or other such "interactive" information service which will accept commands from the viewer throughout the presentation of the program on a real-time basis. On the contrary, prior art systems such as that described by Beyers, II et al. have been limited to customer polling systems, billing systems and the like which do not interactively affect the presentation of the selected service.
To date, the telephone companies have promoted the use of their ISDN digital switching network for routing digital information to the customers. Unfortunately, the telephone lines enter the home as a twisted pair which does not have the bandwidth desired for the transmission of digital video, for example. On the other hand, the cable television companies have promoted the use of the existing broadband coaxial cables for providing digital video data and other information to the viewer. Unfortunately, the CATV systems lack the switching mechanisms needed to route unique programming to each viewer. Indeed, the biggest obstacle to implementation of an interactive information system appears to be the lack of cooperation between the cable television and telephone industries and an agreement regarding common transmission standards and protocols which will be approved by the Federal Communications Commission (FCC). Applicant also knows of no concrete proposals by either camp for implementing a truly interactive digital network which permits the customer to continuously communicate with an information service provider throughout the transmission of the requested programming.
Thus, while there is tremendous market potential for an interactive information services system, no one has taken the lead to provide an interactive information services system which meets the needs and requirements of the customers using conventional communications protocols which are acceptable to the FCC as well as those in the art. It is thus desired to develop an interactive information services system which combines the best characteristics of the cable and telephone transmission systems and to incorporate such characteristics into an independent interactive information services system which will bring the digital revolution into the home. It is also desired that such a system couple the convenience of the home video cassette recorder with the infinite programming flexibility that access to a large library over a network will provide. The present invention has been designed to meet these needs.